The prior art already contains many disclosures and teachings of various vehicle brake and accelerator and clutch pedal assemblies, and it is common to have these pedals arranged to be under the influence of a return spring such that when the pedal is depressed the spring is placed under tension, and when the force on the pedal is relieved, the spring will return the pedal to its original position. Examples of such prior art for controls and pedals and the like are found in U.S. Pat. Nos. 2,458,342 and 2,621,538 and 2,900,970. In these patents, there is a disclosure of an arm, such as a foot or hand actuated arm, which has a return spring attached to it so that when the force on the arm is released, the arm will return to its original position and it does so under the influence of the spring. However, in the prior art arrangement, the further the arm is pivoted or moved toward its intended operative position, the greater is the force of the spring which is resisting that movement. Accordingly, much of the operator's effort in moving the arm is expended in overcoming the force of the spring.
The present invention provides a foot pedial assembly which overcomes the aforementioned shortcoming and problem with regard to the prior art, and, specifically it provides a foot pedal assembly with a return spring arranged in the assembly such that the spring force is actually lessened, rather than increased, when the foot pedal is depressed to its operative position. In accomplishing this objective, more of the force exerted by the operator through the foot on the pedal itself is available for actuating the linkage or the hydraulic system or the like which may be connected with the foot pedal, and the entire assembly is therefore considerably more efficient.
Another objective and advantage of the present invention is to accomplish the aforementioned improvement and advantages and to do so with a foot pedal assembly which is sturdy and reliable and which reduces the resisting force of the spring in direct proportion to the amount that the foot pedal itself is depressed and therefore the more the pedal is depressed the greater is the effective force of the operator's foot on the pedal and its attached mechanism.
Specifically, the present invention provides a foot pedal assembly which, compared to the usual design for a vehicle brake pedal, such as that used in a construction or agricultural tractor wherein it is normal to have a seven-pound force applied by the operator's foot to initially move the pedal from its upward or inactive position, and the present invention results in the lesser force of only five pounds required when the pedal is halfway to its fully depressed position, and it requires only two pounds of force when the pedal is to its fully depressed position. Compared to the prior art where the seven-pound foot force is initially required, as mentioned above, the halfway position would require an 111/2-pound force and the fully depressed position position would require a 16-pound force. Consequently, the present invention requires less force as the pedal is further depressed, and it actually requires 61/2 pounds less than the prior art requires at the halfway position and it requires 14 pounds less than the prior art requires at the fully depressed position.